Third Quarter 2001

Definitions and Explanations

Metropolitan Areas. Standard definitions of metropolitan areas (MA's) are issued by the Office of Management and Budget (OMB) to be used in the presentation of statistics by agencies of the Federal Government. OMB establishes the geographic definition of each area following detailed technical criteria developed with the advice of the Federal Committee on Metropolitan Areas, which is composed of representatives of the major Federal statistical agencies.

Due to the new sample drawn from the 1990 census,
metropolitan/nonmetropolitan data published in 1995 and later are not
directly comparable to data for 1994 and earlier.

The general concept of a metropolitan area is that of a population nucleus of 50,000 and over, generally consisting of a city and its immediate suburbs, together with adjacent communities having a high degree of economic and social integration with that nucleus. MA's are defined in terms of counties, the smallest geographic units for which a wide range of statistical data can be obtained. In New England, however, the definitions are in terms of cities and towns, because these subcounty units are of great local significance and considerable data are available for them.

By the current standards, an area qualifies for recognition as an MA in one of two ways - if there is a city of at least 50,000 population, or a Census Bureau defined urbanized area of at least 50,000 with a total metropolitan population of at least 100,000 (75,000 in New England). In addition to the county containing the main city, an MA also includes additional counties having strong economic and social ties to the central county, determined chiefly by the extent of the Census Bureau urbanized area and census data on commuting to work. New England MA's are defined in terms f a core area and related cities and towns. A metropolitan area may contain more than one city of 50,000 population and may cross State lines. If an MA has more than 1 million population and meets certain other specified requirements, it is termed a consolidated metropolitan statistical area (CMSA), consisting of major components recognized as primary metropolitan statistical areas (PMSA's).

Geographic regions. The four major regions of the United States for which data are presented in this report represent groups of States as follows:

Housing Unit. A housing unit is a house, an apartment, a group of rooms, or a single room occupied or intended for occupancy as separate living quarters. Separate living quarters are those in which the occupants do not live and eat with other persons in the structure and which have direct access from the outside of the building or through a common hall. For vacant units, the criteria of separateness and direct access are applied to the intended occupants whenever possible. If the information cannot be obtained, the criteria are applied to the previous occupants. Tents and boats are excluded if vacant, used for business, or used for extra sleeping space or vacations. Vacant seasonal/migratory mobile homes are included in the count of vacant seasonal/migratory housing units.

Living quarters of the following types are excluded from the housing unit inventory: Dormitories, bunkhouses, and barracks; quarters in predominantly transient hotels, motels, and the like, except those occupied by persons who consider the hotel their usual place of residence; quarters in institutions, general hospitals, and military installations except those occupied by staff members or resident employees who have separate living arrangements.

Occupied Housing Units. A housing unit is occupied if a person or group of persons is living in it at the time of the interview or if the occupants are only temporarily absent, as for example, on vacation. The persons living in the unit must consider it their usual place of residence or have no usual place of residence elsewhere. The count of occupied housing units is the same as the count of households.

Householder. The householder refers to the person (or one of the persons) in whose name the housing unit is owned or rented or, if there is no such person, any adult member, excluding roomers, boarders, or paid employees. If the house is jointly owned by a married couple, either the husband or the wife may be listed first, thereby becoming the reference person, or householder, to whom the relationship of the other household members is recorded. One person in each household is designated as the "householder."

Vacant Housing Units. A housing unit is vacant if no one is living in it at the time of the interview, unless its occupants are only temporarily absent. In addition, a vacant unit may be one which is entirely occupied by persons who have a usual residence elsewhere.

New units not yet occupied are classified as vacant housing units if construction has reached a point where all exterior windows and doors are installed and final usable floors are in place. Vacant units are excluded if they are exposed to the elements, that is, if the roof, walls, windows, or doors no longer protect the interior from the elements, or if there is positive evidence (such as a sign on the house or block) that the unit is to be demolished or is condemned. Also excluded are quarters being used entirely for nonresidential purposes, such as a store or an office, or quarters used for the storage of business supplies or inventory, machinery, or agricultural products.

Vacant sleeping rooms in lodging houses, transient accommodations, barracks, and other quarters not defined as housing units are not included in the statistics in this report. (See section on "Housing Unit.")

Year-round Vacant Units. Beginning in 1990, year-round vacant mobile homes were included as part of the year-round vacant count of housing units. Year-round units are those intended for occupancy at any time of the year, even though they may not be in use the year round. In resort areas, a housing unit which is usually occupied on a year-round basis is considered a year-round unit. As indicated above, year-round units temporarily occupied by persons with usual residence elsewhere are included with year-round vacant units.

Year-round vacant units are classified in the following categories:

Vacant units for rent. This group consists of vacant units offered for rent
and those offered both for rent and sale.

Vacant units for sale only. This group is limited to units for sale only; it excludes units both for rent and sale. If a unit was located in a multi-unit structure which was for sale as an entire structure and if the unit was not for rent, it was reported as "held off market." However, if the individual unit was intended to be occupied by the new owner, it was reported as "for sale."

Vacant units rented or sold. This group consists of year-round vacant units which have been rented or sold but the new renters or owners have not moved in as of the day of interview.

Vacant units held off the market. Included in this category are units held for occasional use, temporarily occupied by persons with usual residence elsewere, and vacant for other reasons. These classifications are described below.

For occasional use. If the vacant unit is not for-rent or for-sale-only but is held for weekends or occasional use thoughout the year, the unit is included in this catagory. Time-shared units are classified in this category if the vacant unit is not for-rent or for-sale-only, but held for use for an individual during the time of interview.

Units Occupied by Persons With Usual Residence Elsewhere. A housing unit which is occupied temporarily by persons who usually live elsewhere is interviewed as a vacant unit provided that a usual place of residence is held for the household which is not offered for rent or for sale. For example, a beach cottage occupied at the time of the interview by a family which has a usual place of residence in the city is included in the count of vacant units. Their house in the city would be reported "occupied" and would be included in the count of occupied units since the occupants are only temporarily absent. Units occupied by persons with usual residence elsewhere (URE) are further classified as seasonal vacant or year round vacant units.

Other vacant. Included in this category are year-round units which were vacant for reasons other than those mentioned above: For example, held for occupancy of a caretaker, janitor; held for settlement of an estate, or held for personal reasons of the owner.

Seasonal Vacant Units. Seasonal housing units are those intended for occupancy only during certain seasons of the year and are found primarily in resort areas. Housing units held for occupancy by migratory labor employed in farm work during the crop season are tabulated as seasonal. As of the first quarter 1986 vacant seasonal mobile homes are being counted as a part of the seasonal housing inventory.

Vacancy and Homeownership Rates. In this report several measures are shown for vacant housing units that are on the market for rent or for sale only. Measures are also shown for homeownership rates.

Rental Vacancy Rate. The rental vacancy rate is the proportion of the rental inventory which is vacant for rent. In tables 1 and 2, the rates are computed using the following formula:

Rental Vacancy Rates by Selected Characteristics. The rental vacancy rates shown in table 3 are the percent relationship of the vacant year-round units for rent with a specific characteristic (such as 3-room units) to all rental units with that specific characteristic. Excluded from the denominator are year-round units rented but awaiting occupancy. The rates are computed as follows:

For example, the numerator for the rental vacancy rate for units with 3 rooms is all vacant year-round for rent units with 3 rooms. The denominator is: (1) all renter occupied units with 3 rooms and (2) vacant year-round units for rent with 3 rooms.

Homeowner Vacancy Rate. The homeowner vacancy rate is the proportion of the homeowner inventory which is vacant for sale. In tables 1 and 2, the rates are computed using the following formula:

Homeowner Vacancy Rates by Selected Characteristics. The homeowner vacancy rates shown in table 3 are the percent relationship of the vacant year-round units for sale with a specific characteristic (such as 3-room units) to all homeowner units with that specific characteristic. Excluded from the denominator are year-round units sold but awaiting occupancy. The rates are computed as follows:

For example, the numerator for the homeowner vacancy rate for units with 3 rooms is all vacant year-round units for sale only with 3 rooms.

Homeownership Rates. The proportion of households that are owners is termed the homeownership rate. It is computed by dividing the number of households that are owners by the total number of households (table 5 and 6). The formula is as follows:

Homeownership by Age of Householder. This homeownership rate is calculated by dividing the number of owner household in a particular age group by the total number of occupied households in that age group (table 7).

Other Occupancy and Vacancy Rates. The percent distribution of vacant and occupied housing units, shown in tables 10 and 11, are shown as a percent of all housing units and are computed using the following formula:

For example, the numerator for the for-rent rate is all year-round vacant units for rent. The denominator is all housing units.

Tenure. A unit is owner occupied if the owner or co-owner lives in the unit, even if it is mortgaged or not fully paid for. A cooperative or condominium unit is "owner occupied" only if the owner or co-owner lives in it. All other occupied units are classified as "renter occupied," including units rented for cash rent and those occupied without payment of cash rent.

Number of Rooms. Includedl in the count of rooms were whole rooms such as living rooms, dining rooms, bedrooms, kitchens, finished basements or attics, recreation rooms, permanently enclosed sun porches which are suitable for year-round use, and lodger's rooms. A partially divided room, such as dinette next to a kitchen or living room was counted as a separate room only if there was a partition from floor to ceiling, but was not counted as a room if the partition consisted solely of shelves or cabinets. Not included in the count of rooms were bathrooms, halls, foyers or vestibules, balconies, closets, alcoves, pantries, strip or pullman kitchens, laundry or furnace rooms, unfinished attics or basements, open porches, sun porches not suited for year-round use, unfinished space used for storage, mobile homes or trailers used only as bedrooms, and offices used only by persons not living in the unit. A room used by the occupants of more than one unit was included with the unit from which it could be most easily reached.

The median number of rooms is the theoretical value which divides the housing units equally, one-half having more rooms and one-half having fewer rooms than the median. In the computation of the median, a continuous distribution was assumed. For example, when the median was in the three-room group, the lower and upper limits were assumed to be 2.5 and 3.5, respectively. Tenths were used in the computation of the median to permit comparisons.

Number of Bedrooms. Rooms used mainly for sleeping, even if used for other purposes, were counted as bedrooms. Also included in the count of bedrooms were rooms reserved for sleeping, such as guest rooms, even though used infrequently. A room used mainly for other purposes, although also used for sleeping, such as a living room with a hide-away bed, was not counted as a bedroom. A one-room apartment, therefore, was reported as having no bedroom.

Number of Housing Units in Structure. A structure is a separate building which either has open space on all four sides or is separated from other structures by dividing walls that extend from ground to roof. In double houses, row houses, and houses attached to nonresidential structures, each building is a structure if the common wall between them goes from ground to roof. Sheds and private garages which adjoin houses are not counted as separate structures. In apartment developments, each building with open space on all sides is considered a separate structure. The count of housing units in a structure is the total number of units in the structure, both occupied and vacant units. In the tabulations, occupied mobile homes or trailers, tents, and boats are included in the category one housing unit in structure.

The statistics reflect the number of housing units in the structure in which they are located, rather than the number of residential structures. In the quarterly surveys, data were obtained on the number of housing units in the structure, regardless of the type of structures in which the unit was located.

Year Structure Built. "Year structure built" refers to the date the original construction of the structure was completed, and not to any later remodeling, addition, or conversion. The figures on the number of units built during a given period relate to the number of units in existence at the time of interview. For both occupied and vacant mobile homes, "model year" is the year built.

Duration of Vacancy. The length of time a housing unit was vacant was computed from the day the unit became vacant until the day of the interview. The data, therefore, do not provide a direct measure of the total length of time units remain vacant. For newly constructed units, the duration of vacancy represents the time period since the date when the unit was considered a vacant housing unit, that is, when construction had reached the point that all exterior windows and doors were installed and final usable floors were in place. For recently converted or merged units, the length of time is reported from the date the conversion or merger was completed. For units temporarily occupied by persons with a usual residence elsewhere, duration of vacancy is the length of time since the last usual residents moved; if the unit was always occupied by persons with usual residence elsewhere the time is reported from the date the unit was originally ready for occupancy.

The time intervals used in the tables represent full months, calculated from a date in the month to the same date the following month. For example, if the unit became vacant on July 29 and was still vacant on the day interviewed, September 20, the time reported would be "1 to 2 months," meaning that the unit had been vacant for more than 1 month but less than 2 months. Or if the unit became vacant on August 25 and was still vacant on September 20, the time reported would be "less than 1 month."

Previous Occupancy. A unit was classified as being "previously occupied" if the unit had ever been occupied or if the unit was occupied by persons with a usual residence elsewhere. If a previously occupied unit had been converted into several housing units, each unit was classified as being previously occupied. Also, housing units that resulted from conversion of nonresidential space or from a merger was reported as being previously occupied. Only vacant newly constructed units were classified as "not previously occupied."

Contract Rent. For renter-occupied units, the contract rent is the monthly rent agreed upon regardless of any furnishings, utilities, or services that may be included. For vacant units, rent is the amount asked for the unit at the time of interview; the amount may differ from the rent contracted for when the unit is occupied. Data for contract rent excludes units for which no cash rent is paid. As in the 1980 census, the statistics are limited to specified rental units. These data exclude rents for renter-occupied and vacant for-rent single-family structures on places of 10 acres or more.

The median monthly rent is the rent which divides the series into two equal parts, one-half of the units with rents higher than the median and the other half with rents lower than the median. In the computation of the median, a continuous distribution was assumed, and the limits of the class intervals were assumed to stand at the midpoint of the 1-dollar interval between the end of one of the rent groups and the beginning of the next. For example, the limits of the interval designated $250 to $299 were assumed to be $249.50 and $299.50.

Inclusion of Utilities in Rent. The utilities included in the inquiry were electricity, gas, water, oil, coal, wood, and kerosene, etc. The statistics reflect whether all or some or none of these utilities are provided for in the amount of rent asked at the time of the interview. A unit was classified as having "all utilities included" if the cost of the utilities are included in the rent at no additional cost to the renter or if the utilities would not be used by the renter. A unit was classified as having "some or none included" if all or part of the utilities are to be paid for separately by the renter in addition to the rent asked. Data on the inclusion of utilities are limited to vacant units for which rent is reported. No data on utilities are collected for renter-occupied units.

Value. Value is the respondent's estimate of how much the property would sell for on the current market. For vacant units, value is the sales price asked for the property at the time of the interview and may differ from the price at which the property is sold. The "sales price asked" includes the price of a one-housing-unit structure and the land on which it is located. The "sales price asked" may also include additional structures such as garages, sheds, barns, etc.

In this report, statistics on value for owner-occupied units and vacant for-sale-only units are limited to specified homeowner units which includes all one-housing unit structures located on places of less than 10 acres, without a commercial establishment or medical office on the property and with only one-housing unit on the property.

The median value or sales price is the amount which divides the series into two equal parts, one-half of the units with values higher than the median and the other half with values lower than the median. The median was computed on the basis of more detailed tabulation groups than are shown in the tables and was rounded to the nearest hundred dollars.